Data commit

Task/Floyds-triangle/C/floyds-triangle.c

@@ -0,0 +1,62 @@
+#include <stdio.h>
+
+void t(int n)
+{
+	int i, j, c, len;
+
+	i = n * (n - 1) / 2;
+	for (len = c = 1; c < i; c *= 10, len++);
+	c -= i; // c is the col where width changes
+
+#define SPEED_MATTERS 0
+#if SPEED_MATTERS	// in case we really, really wanted to print huge triangles often
+	char tmp[32], s[4096], *p;
+
+	sprintf(tmp, "%*d", len, 0);
+
+	inline void inc_numstr(void) {
+		int k = len;
+
+	redo:	if (!k--) return;
+
+		if (tmp[k] == '9') {
+			tmp[k] = '0';
+			goto redo;
+		}
+
+		if (++tmp[k] == '!')
+			tmp[k] = '1';
+	}
+
+	for (p = s, i = 1; i <= n; i++) {
+		for (j = 1; j <= i; j++) {
+			inc_numstr();
+			__builtin_memcpy(p, tmp + 1 - (j >= c), len - (j < c));
+			p += len - (j < c);
+
+			*(p++) = (i - j)? ' ' : '\n';
+
+			if (p - s + len >= 4096) {
+				fwrite(s, 1, p - s, stdout);
+				p = s;
+			}
+		}
+	}
+
+	fwrite(s, 1, p - s, stdout);
+#else // NO_IT_DOESN'T
+	int num;
+	for (num = i = 1; i <= n; i++)
+		for (j = 1; j <= i; j++)
+			printf("%*d%c",	len - (j < c), num++, i - j ? ' ':'\n');
+#endif
+}
+
+int main(void)
+{
+	t(5), t(14);
+
+	// maybe not
+	// t(10000);
+	return 0;
+}